Funds are requested to set up a truly national Resource for protein crystallography. This Resource will house two high speed data collection systems which will be available to protein crystallography groups in the United States. The first system which presently consists of a standard, fixed-source X-ray generator and one multiwire area X-ray detector can, as has been demonstrated, collect data about 10 times faster than a standard diffractometer and can collect data efficiently for protein crystals with unit cell dimensions up to about 120 Angstroms. The second system consisting of a rotating anode X-ray source and up to 6 or more area detectors will be at least one hundred times faster than a standard diffractometer and will be able to collect data efficiently for protein crystals with unit cell dimensions up to 300 to 400 Angstroms. This resource will be directed by an advisory board composed of well known protein crystallographers and biochemists from all regions of the United States. This board will provide scientific direction, establish the Resource guidelines and assure equitable access to the Resource by all user groups. Core researches wil also be an improtant activity of the resource since one of its aims is to continue to develop better area detectors and better methods to collect protein crystallographic data. The third important activity of the resource is the training of other protein crystallographers on the new methods of data collection, therefore every two years the resource staff will set up workshops and seminars on this subject. Protection crystallographers are also encouraged to spend a short period of time (about one month) at the resource in order to get some hand-on experience.